In general, semiconductor manufacturing processes require high precision, and thus, high cleanliness and special production technology have been demanded.
For this reason, semiconductor devices are manufactured in a state in which foreign substances contained in the air are completely prevented from contacting the devices, that is, in a vacuum state.
Thus, a technique for sealing a vacuum work area in a semiconductor manufacturing apparatus from the air also has substantial influence on the quality of semiconductor products.
For such a semiconductor manufacturing process, a process chamber in which an integration process of a semiconductor device is performed, a vacuum pump which suctions the air in the process chamber, and a vacuum valve, which is installed between the process chamber and the vacuum pump and adjusts the transfer of the suction force of the vacuum pump, are installed.
In the configuration of such a vacuum valve, the blade, which is connected to a driving member and opens/closes a moving passage using the driving force of the driving member, functions to open/close the moving passage by being vertically or horizontally moved depending on whether to operate the driving member. Thus, the blade plays a very important role to improve work efficiency by maintaining the cleanliness inside the process chamber.
Therefore, when the moving passage is closed, the blade is preferably designed to have a high sealing performance with respect to the moving passage.
Among documents related to such blades, patent document 1 titled “installation of valve plate on valve rod” disclosed in Korean Patent Application Laid-open Publication No. 10-2011-0102328 discloses an installation of a valve plate on a valve rod using a cross member extending across the valve rod. The cross member is connected to the valve rod at a central connection point and is connected to the valve plate at two or more side connection points located on both sides of the central connection point. When installing the valve plate on the valve rod such that there is a gap between the cross member and the valve plate in a central section including cross member sections which are folded at the central connection point at the central connection point and both the sides, the valve plate is configured to be rotatable around a rotation axis perpendicular to the valve rod relative to the valve rod by using a torsion of the cross member. Thus, there was a merit in that when the valve plate closed a valve opening portion, the valve plate pressed the valve opening part with a uniform force and a tight sealing state could thereby be maintained.
However, the above-mentioned “installation of valve plate on valve rod” disclosed in patent document 1 had a problem in that as the valve rod worn and the connections of the valve plate, a vertical axis, and the like were loosened due to repetitive operation, the valve plate, when closing the valve opening, could not precisely close the valve opening part, and thus, the cleanliness inside a process chamber was decreased, foreign substances or the like penetrated into a valve housing, and particles were thereby generated.
In addition, the above-mentioned “installation of valve plate on valve rod” disclosed in patent document 1 had a structure including the valve opening part and the valve plate in which a surface-to-surface contact was made, and thus had a problem in that the valve plate, which horizontally moved to open/close the valve opening, did not moves horizontally but obliquely due to a minute change in an amount of compressed air actuating the cylinder, a piston raising output, a torque applied to the valve plate, and a connection points of components, or the like, so that a separation phenomenon occurred in a surface at which the valve plate and the valve opening met, and accordingly, sealing performance was decreased and the function as a valve used inside a process chamber was lost.